Heat sink for power module

1. A power module comprising: a power device; and a heat sink to which heat generated by the power device is transmitted, the heat sink including: a refrigerant passage in which a cooling medium that dissipates the heat generated by the power device flows, the refrigerant passage is defined by a surface and a backside, and the power device is disposed in proximity to said surface; and a corrugated fin body arranged in the refrigerant passage, wherein the corrugated fin body has crests and troughs that extend in a parallel manner and side walls each of which connects a corresponding one of the crests with an adjacent one of the troughs, the crests are joined to the surface, and the troughs are joined to the backside, wherein each adjacent pair of the side walls and the corresponding one of the crests or the adjacent one of the troughs arranged between the each adjacent pair of side walls form a fin, wherein a first louver is formed in one of the each adjacent pair of the side walls, a second louver is formed in another of the each adjacent pair of the side walls, and wherein the first and second louvers operate to, at least, rotate the cooling medium flowing in the fin to the other side wall past the corresponding one of the crests or the adjacent one of the troughs.

2. The power module according to claim 1 , wherein the first louver and the second louver are inclined in opposite directions with respect to a direction in which the crests and the troughs extend along the surface and the backside of the refrigerant passage.

3. The power module according to claim 1 , wherein each of the first and second louvers is formed through bending of a portion of a corresponding one of the side walls defined by a cut.

4. The power module according to claim 3 , wherein the first louver louvers is two first louvers formed in the one of the each adjacent pair of the side walls, wherein the second louver is two second louvers formed in the another of the each adjacent pair of the side walls; and wherein the two first or second louvers formed in each of the side walls are located at different positions in a direction along a height of a wave formed by the corrugated fin body, the height being defined in a direction between the surface and the backside of the refrigerant passage, and the two first or second louvers are formed through bending of portions of the side wall defined by cuts in opposite directions.

5. The power module according to claim 1 , wherein the first louvers and the second louvers are inclined in the same direction with respect to a direction in which the crests and the troughs extend along the surface and the backside of the refrigerant passage, and wherein through holes are formed at positions corresponding to both ends of each side wall in the direction along a height of the side wall.

6. The power module according to claim 1 , wherein a wave formed by the corrugated fin body has a rectangular shape.